A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of making tea. It gives a clear starting point for the process. It uses the rule of Topic Sentence because it sets up the main topic without going into details. Why other lines are not chosen? The other paragraphs are not chosen because they do not stand alone. For example, Paragraph 2 starts with 'Once boiled,' which needs the first step for context. Paragraph 3 starts with 'Allow the tea to steep,' which also needs the previous steps. Paragraph 4 starts with 'Finally,' which shows it is the last step and needs earlier steps to make sense.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the process of making tea. It uses the rule of Conclusive Words with 'Finally,' which shows it is the end of the steps. It also summarizes the final action of serving and enjoying the tea.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects with Paragraph 1 because it uses the Connector strategy. The phrase 'Once boiled' shows that it follows the action of boiling water. This shows a logical order of steps in making tea.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects with Paragraph 2 because it follows the logical order of making tea. After pouring the water, the next step is to allow the tea to steep. This shows a clear progression in the process.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects with Paragraph 3 because it shows the next step after steeping the tea. The word 'Finally' indicates that this is the last step in the process of making tea, showing a clear order.